1. Field of the Invention
The present invention pertains to digital image processing. More particularly, this invention relates to automatically producing an optimized color image from a negative image and its corresponding developed print image.
2. Description of the Related Art
Photographic prints or print images have traditionally been used for visual presentation. The photographic prints are typically developed from negative images on a film by photo development labs or stores. The photographic prints are hereinafter referred to as "prints" and the negative images are hereinafter referred to as "negatives".
With the advances in computer technologies, it is now possible to store the prints and negatives in a computer system. This can be done using a scanner that converts the image on the print or negative into a digital image. The scanner can convert either the print into a digital print image, or the negative into a digital negative image. As is known, a digital image includes image pixels (or dots) arranged in a matrix. The data for each image pixel are then stored in a storage device of the computer system. The data for an image pixel typically include color and luminance information of that pixel. The data for an image pixel may also include other information. The digital image can be retrieved from the storage device of the computer system for imaging (e.g., to be displayed or printed). In addition, the digital image can also be digitally altered in the computer system. Moreover, the digital image can be transmitted to another computer system located at a remote site via a communication network. This also allows real time viewing of the image.
As is known, the prints typically have far better color appearance than their corresponding negatives. This is due to the fact that the photo development process of the prints typically employs a sophisticated developing process which optimizes the color appearance of the prints. The sophisticated developing process detects any color deficiency (or excessive color) on a negative and then makes appropriate color compensation on the corresponding print. On the other hand, due to the advantages of film, a negative typically has far more detail than its corresponding print. In addition, the negative also looks much sharper than its corresponding print.
However, a problem typically arises when the user wants to generate a digital image from either a negative or the corresponding print. If a print is scanned into a digital image, the resolution of the digital print image is typically not as desirable as that of the digital image produced from the corresponding negative. If a negative is scanned into a digital image, the color appearance of the digital negative image may not be as desirable as that of the digital image produced from the corresponding print, or vice versa. Furthermore, a scanned print image typically cannot be digitally enlarged without artifacts while the scanned negative image can be enlarged due to its higher resolution. However, it may be highly desirable to retain the advantages of both the negative and print.
One prior art solution to this problem is to manually correct any color deficiency contained in the negative. This is typically done using a photo-retouching tools by an expert in the field. One disadvantage of this prior art approach is that it typically requires expertise in accomplishing the work. An ordinary person does not have the skill and expertise to recognize any color deficiency or excessive color in a negative, nor does he have the expertise or skill to do the required retouching work. Another disadvantage associated with the prior art approach is that it is typically a very time consuming process and requires a great degree of patience.
Thus, there exists a need to automatically produce an optimized color image from a negative color image and its developed print image without user intervention.